imgact_linux.c revision 119842
1/*- 2 * Copyright (c) 1994-1996 S�ren Schmidt 3 * All rights reserved. 4 * 5 * Based heavily on /sys/kern/imgact_aout.c which is: 6 * Copyright (c) 1993, David Greenman 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer 13 * in this position and unchanged. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: head/sys/i386/linux/imgact_linux.c 119842 2003-09-07 13:23:45Z bde $"); 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/exec.h> 38#include <sys/imgact.h> 39#include <sys/imgact_aout.h> 40#include <sys/kernel.h> 41#include <sys/lock.h> 42#include <sys/mman.h> 43#include <sys/mutex.h> 44#include <sys/proc.h> 45#include <sys/resourcevar.h> 46#include <sys/vnode.h> 47 48#include <vm/vm.h> 49#include <vm/vm_kern.h> 50#include <vm/vm_param.h> 51#include <vm/pmap.h> 52#include <vm/vm_map.h> 53#include <vm/vm_extern.h> 54 55#include <i386/linux/linux.h> 56 57static int exec_linux_imgact(struct image_params *iparams); 58 59static int 60exec_linux_imgact(struct image_params *imgp) 61{ 62 const struct exec *a_out = (const struct exec *) imgp->image_header; 63 struct vmspace *vmspace; 64 vm_offset_t vmaddr; 65 unsigned long virtual_offset, file_offset; 66 vm_offset_t buffer; 67 unsigned long bss_size; 68 struct thread *td = curthread; 69 int error; 70 71 if (((a_out->a_magic >> 16) & 0xff) != 0x64) 72 return -1; 73 74 /* 75 * Set file/virtual offset based on a.out variant. 76 */ 77 switch ((int)(a_out->a_magic & 0xffff)) { 78 case 0413: 79 virtual_offset = 0; 80 file_offset = 1024; 81 break; 82 case 0314: 83 virtual_offset = 4096; 84 file_offset = 0; 85 break; 86 default: 87 return (-1); 88 } 89 bss_size = round_page(a_out->a_bss); 90#ifdef DEBUG 91 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n", 92 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size); 93#endif 94 95 /* 96 * Check various fields in header for validity/bounds. 97 */ 98 if (a_out->a_entry < virtual_offset || 99 a_out->a_entry >= virtual_offset + a_out->a_text || 100 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK) 101 return (-1); 102 103 /* text + data can't exceed file size */ 104 if (a_out->a_data + a_out->a_text > imgp->attr->va_size) 105 return (EFAULT); 106 /* 107 * text/data/bss must not exceed limits 108 */ 109 mtx_assert(&Giant, MA_OWNED); 110 if (a_out->a_text > maxtsiz || 111 a_out->a_data + bss_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) 112 return (ENOMEM); 113 114 VOP_UNLOCK(imgp->vp, 0, td); 115 116 /* copy in arguments and/or environment from old process */ 117 error = exec_extract_strings(imgp); 118 if (error) 119 goto fail; 120 121 /* 122 * Destroy old process VM and create a new one (with a new stack) 123 */ 124 exec_new_vmspace(imgp, &linux_sysvec); 125 vmspace = imgp->proc->p_vmspace; 126 127 /* 128 * Check if file_offset page aligned,. 129 * Currently we cannot handle misalinged file offsets, 130 * and so we read in the entire image (what a waste). 131 */ 132 if (file_offset & PAGE_MASK) { 133#ifdef DEBUG 134 printf("imgact: Non page aligned binary %lu\n", file_offset); 135#endif 136 /* 137 * Map text+data+bss read/write/execute 138 */ 139 vmaddr = virtual_offset; 140 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 141 a_out->a_text + a_out->a_data + bss_size, FALSE, 142 VM_PROT_ALL, VM_PROT_ALL, 0); 143 if (error) 144 goto fail; 145 146 error = vm_mmap(kernel_map, &buffer, 147 round_page(a_out->a_text + a_out->a_data + file_offset), 148 VM_PROT_READ, VM_PROT_READ, 0, 149 (caddr_t) imgp->vp, trunc_page(file_offset)); 150 if (error) 151 goto fail; 152 153 error = copyout((void *)(uintptr_t)(buffer + file_offset), 154 (void *)vmaddr, a_out->a_text + a_out->a_data); 155 156 vm_map_remove(kernel_map, buffer, 157 buffer + round_page(a_out->a_text + a_out->a_data + file_offset)); 158 159 if (error) 160 goto fail; 161 162 /* 163 * remove write enable on the 'text' part 164 */ 165 error = vm_map_protect(&vmspace->vm_map, 166 vmaddr, 167 vmaddr + a_out->a_text, 168 VM_PROT_EXECUTE|VM_PROT_READ, 169 TRUE); 170 if (error) 171 goto fail; 172 } 173 else { 174#ifdef DEBUG 175 printf("imgact: Page aligned binary %lu\n", file_offset); 176#endif 177 /* 178 * Map text+data read/execute 179 */ 180 vmaddr = virtual_offset; 181 error = vm_mmap(&vmspace->vm_map, &vmaddr, 182 a_out->a_text + a_out->a_data, 183 VM_PROT_READ | VM_PROT_EXECUTE, 184 VM_PROT_ALL, 185 MAP_PRIVATE | MAP_FIXED, 186 (caddr_t)imgp->vp, file_offset); 187 if (error) 188 goto fail; 189 190#ifdef DEBUG 191 printf("imgact: startaddr=%08lx, length=%08lx\n", 192 (u_long)vmaddr, a_out->a_text + a_out->a_data); 193#endif 194 /* 195 * allow read/write of data 196 */ 197 error = vm_map_protect(&vmspace->vm_map, 198 vmaddr + a_out->a_text, 199 vmaddr + a_out->a_text + a_out->a_data, 200 VM_PROT_ALL, 201 FALSE); 202 if (error) 203 goto fail; 204 205 /* 206 * Allocate anon demand-zeroed area for uninitialized data 207 */ 208 if (bss_size != 0) { 209 vmaddr = virtual_offset + a_out->a_text + a_out->a_data; 210 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr, 211 bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 212 if (error) 213 goto fail; 214#ifdef DEBUG 215 printf("imgact: bssaddr=%08lx, length=%08lx\n", 216 (u_long)vmaddr, bss_size); 217#endif 218 219 } 220 /* Indicate that this file should not be modified */ 221 mp_fixme("Unlocked v_flag access"); 222 imgp->vp->v_vflag |= VV_TEXT; 223 } 224 /* Fill in process VM information */ 225 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT; 226 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT; 227 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset; 228 vmspace->vm_daddr = (caddr_t)(void *)(uintptr_t) 229 (virtual_offset + a_out->a_text); 230 231 /* Fill in image_params */ 232 imgp->interpreted = 0; 233 imgp->entry_addr = a_out->a_entry; 234 235 imgp->proc->p_sysent = &linux_sysvec; 236 237fail: 238 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td); 239 return (error); 240} 241 242/* 243 * Tell kern_execve.c about it, with a little help from the linker. 244 */ 245static struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" }; 246EXEC_SET(linuxaout, linux_execsw); 247